As shown in FIGS. 7 and 8, a waveguide type optical member a such as a waveguide or an AWG (arrayed waveguide grating) and fiber arrays b are aligned by means of an aligning mechanism, and immovably bonded for assembling.
In this case, the respective end faces as bonding faces are ground, for example, orthogonally as shown in FIG. 7, or obliquely as shown in FIG. 8. The obliquely ground end faces can have various angles, but presently those of 8 degrees are mainly used.
The conventional apparatus for aligning and immovably bonding a waveguide type optical member and fiber arrays is composed of a fixing base unit for holding the waveguide type optical member, and aligning units installed on both sides of it for holding and moving fiber arrays for alignment, and in general, each of the aligning units is composed of a six-axis stage mechanism of X, Y, Z, θx, θy and θz, where X denotes right-left direction; Y, vertical direction; Z, advancing and retreating direction (or longitudinal direction); θx, a rotating direction around X axis; θy, a rotating direction around Y axis; and θz, a rotating direction around Z axis.
For a waveguide type optical member and fiber arrays having orthogonally or obliquely ground end faces, the conventional aligning units designed for orthogonally ground end faces are used also for obliquely ground end faces, or special aligning units allowing the tilting of Y stage are used for obliquely ground end faces.
In the case where aligning units designed for orthogonally ground end faces are used for assembling the optical member and the fiber arrays respectively having obliquely ground end faces, when the fiber arrays b are moved along the oblique end faces of the waveguide type optical member a, a Z stage for longitudinal direction and a Y stage for vertical direction are used as shown in FIG. 10. That is, the Y stage is actuated to raise the fiber array b a little and subsequently the Z stage is actuated to let a fiber array b advance a little. These actions are repeated alternately to move the fiber array along a stairs-like locus.
On the other hand, in the case where a special aligning unit designed for obliquely ground end faces is used for assembling an optical member and either of two fiber arrays respectively having end faces of, for example, 8 degrees, a spacer worked to have an angle of 8 degrees is kept behind the Y stage, and the Y stage is fixed as tilted, while the fiber array is moved along the oblique end face of the waveguide type optical member.
In the case where an aligning unit designed for orthogonally ground end faces is used for aligning an optical member and either of two fiber arrays respectively having obliquely ground end faces, the two stages, i.e., the Y stage for vertical direction and the Z stage for longitudinal direction must be actuated alternately. So, it has the following problems: (a) it takes a long time for alignment, (b) if the moving distance of the Z stage is too long, the fiber array may be caused to collide with the waveguide type optical member, and (c) in the case where software is used for controlling those actions, it takes a time for adjustment.
On the other hand, in the case where a special aligning unit designed for obliquely ground end faces is used, it can be generally used only for a set angle, and even if it is attempted to use the aligning unit exchanging the spacer for a one having a different angle, adjustment is inconveniently necessary for achieving a desired accuracy. Furthermore, if an aligning unit is prepared for every angle, there arises a problem of high cost.
The object of this invention is to solve these problems.